Carbocyclic Nucleosides (Carbanucleosides) as New Therapeutic Leads

Many structural modifications have been made on the naturally occurring nucleosides in the search for medicinal agents that will interfere with the utilization of the natural compounds. One such area of pursuit has been the replacement of the oxygen of the ribofuranose ring of common nucleosides with a methylene unit (resulting in a cyclopentyl ring) leading to biologically meaningful carbanucleosides (carbocyclic nucleosides). This review calls attention to new methods for preparing these compounds in enantiomeric forms with various heterocyclic bases and ring contracted and expanded cyclopentyl substituents.